Hydro Dams

February 3rd, 2010

The Xingu River flows through much of Brazil’s rainforest and joins the Amazon before emptying into the ocean. Stretching from its head waters along 1450 km of countryside, it empties water at rates varying from 1000 to a staggering 30000 cubic metres per second. Along its length fourteen native tribes depend upon it for survival.

If the native tribes were left to their own devices then they would likely remain until a natural cataclysm, like a meteor, ruined the vast extent of countryside.

Now, in our unquenchable thirst for energy, we’ve set our eyes upon the Xingu’s great hydroelectric potential. At an estimated cost of $16B and a flooded area of 500 square kilometres, we expect a capacity of 11000 MW. However, silt will likely end this dam’s lifetime in about 200 years. A natural cataclysm would be in 100 000 years. Which is more sustainable?

river

Dry Cells

December 23rd, 2009

Tis the season of portable energy. Phones, radios, toys all perform commanded functions given a supply of electrical energy. A common type is the 23 grams AA alkaline dry cell battery.

So expedient are these that the US produces over 3 billion dry cell batteries annually. Assuming all are alkaline, they consume about 1.38e6kg of Zinc, another 1.38e7kg of Iron and 1.725kg of Manganese. The remainder is electrolyte, plastic and paper carbon.

The energy cost of this material includes mining from the Earth, refining, transporting, fabricating, transporting, distributing, transporting, and, if lucky, recycling. All this effort is to annually provide 4.37e13 Joules (for all 3 billion batteries at 2700mAh).

If the same energy was available as food it would feed about 12000 people over the year. Yet there is no way that 12000 people could, unassisted by machines, ever make 3 billion batteries a year. Is this unbalanced application of energy wise or sustainable?

battery

Debt

December 11th, 2009

Borrow now as an investment in the future. Use the investment to make profits to pay back the debt. The mantra of economics trumpets this message over and over.

The US national gross debt is about $10trillion. New York State has a debt of $128billion (including public authorities). New York City has a debt of $59billion.  Personal household debt for the US is $11.4trillion. Residents of the US maintain a revolving credit card debt of $1trillion. Add this up to find a per capita debt load of over $73 510 per person. Yet, in New York City, the per capita annual salary is about $48 631.

Energetic work is needed to pay the debt. If the energy supply falters what does this mean for the future that we have so fully indentured?

 

 

Magnitude

December 3rd, 2009

For a short time in the life span of the Earth, humans have made a significant impression as seen in the following.

Global Annual Data Indicator

10000 BCE

2008 CE

Human population

2 000 000

6,692,030,277

Meat production (land)

14 600tonnes

280,900,000 tonnes

Fish production

~0

144 200 000 tonnes

Cultivated grain

0

2 100 000 000 tonnes

Land area

13 423 420 000ha

13 423 420 000ha

Life supporting area

(cropland, shrubland,

grassland, savanna, forest)

10 297 900 000ha

10 297 900 000ha

Cropland area

0

3 191 300 304 ha

Ammonia (NH3) production

0

126 872 000 tonnes

Urea production

0

66 302 000 tonnes

Energy use

7.6e15 Joules

4.66e20 Joules

In 12000 brief years, our species has become a significant effector on the Earth’s surface. Will we be able to continue to prosper as the impact of our actions reverbrates?